Although fungi have been recognized as important pathogens for the last century, they were for many years considered unusual and limited to certain endemic areas. As a result, the development of antifungal agents has lagged far behind that of antibacterial agents. The first important antifungal drug, amphotericin B (AmB), introduced in 1955, was the mainstay of therapy until the 1980s when the first generation of triazole antifungal agents, i.e. ketoconazole, fluconazole, and itraconazole was introduced. During the last two decades, the incidence of systemic fungal infections has increased dramatically, associated with the development of transplantation techniques, advances in chemotherapy, and the appearance of the AIDS epidemic.